Bryan and Adam have a total of $180.
Bryan spends
14 of his money and
Adam spends
18 of his money.
They spend $31 altogether.
- How much does Bryan have at first?
- How much does Adam have in the end?
|
Bryan |
Adam |
Before |
4 u |
8 p |
Change |
- 1 u |
- 1 p |
After |
3 u |
7 p |
(a)
Amount that Bryan has at first = 4 u
Amount that Adam has at first = 8 p
Total amount that they have = 4 u + 8 p = 180 --- (1)
Total amount that they spend = 1 u + 1 p = 31 --- (2)
(2)
x 8 8 u + 8 p = 248 --- (3)
(3) - (1)
(8 u + 8 p) - (4 u + 8 p) = 248 - 180
8 u + 8 p - 4 u - 8 p = 248 - 180
8 u - 4 u + 8 p - 8 p = 68
8 u - 4 u = 68
4 u = 68
1 u = 68 ÷ 4 = 17
Substitute 1 u = 17 into (1).
4 u + 8 p = 180
4 x 17 + 8 p = 180
68 + 8 p = 180
8 p = 180 - 68 = 112
1 p = 112 ÷ 8 = 14
Amount that Bryan has at first
= 4 u
= 4 x 17
= $68
(b)
Amount that Adam has in the end
= 8 p - 1 p
= 7 p
= 7 x 14
= $98
Answer(s): (a) $68; (b) $98